Catalysts for control of long chain branching

ABSTRACT

Catalyst systems and methods for making and using the same are disclosed. A catalyst composition is provided that includes a catalyst compound supported to form a supported catalyst system, the catalyst compound including: 
     
       
         
         
             
             
         
       
     
     where each of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7  and X are as discussed herein.

PRIORITY INFORMATION

This application is a Divisional of U.S. 371 National Stage applicationSer. No. 15/566,286, filed Oct. 13, 2017 and published as U.S.Publication No. 2018-0079838 A1 on Mar. 22, 2018, which claims thebenefit of International Application Number PCT/US2016/027563, filedApr. 14, 2016 and published as WO 2016/168479 on October 20, 2016, whichclaims the benefit to U.S. Provisional Application 62/148,922, filedApr. 17, 2015, the entire contents of which are incorporated herein byreference in its entirety.

BACKGROUND

Ethylene alpha-olefin (polyethylene) copolymers are typically producedin a low pressure reactor, utilizing, for example, solution, slurry, orgas phase polymerization processes. Polymerization takes place in thepresence of catalyst systems such as those employing, for example, aZiegler-Natta catalyst, a chromium based catalyst, a metallocenecatalyst, or combinations thereof.

A number of catalyst compositions containing single site, e.g.,metallocene, catalysts have been used to prepare polyethylenecopolymers, producing relatively homogeneous copolymers at goodpolymerization rates. In contrast to traditional Ziegler-Natta catalystcompositions, single site catalyst compositions, such as metallocenecatalysts, are catalytic compounds in which each catalyst moleculecontains one or only a few polymerization sites. Single site catalystsoften produce polyethylene copolymers that have a narrow molecularweight distribution. Although there are single site catalysts that canproduce broader molecular weight distributions, these catalysts oftenshow a narrowing of the molecular weight distribution as the reactiontemperature is increased, for example, to increase production rates.Further, a single site catalyst will often incorporate comonomer amongthe molecules of the polyethylene copolymer at a relatively uniformrate. The molecular weight distribution and the amount of comonomerincorporation can be used to determine a composition distribution.

The composition distribution of an ethylene alpha-olefin copolymerrefers to the distribution of comonomer, which form short chainbranches, among the molecules that comprise the polyethylene polymer.When the amount of short chain branches varies among the polyethylenemolecules, the resin is said to have a broad composition distribution(BCD). When the amount of comonomer per 1000 carbons is similar amongthe polyethylene molecules of different chain lengths, the compositiondistribution is said to be “narrow”.

Further, the composition distribution may have variation in the amountof comonomer incorporated into long chains versus short chains.

The composition distribution is known to influence the properties ofcopolymers, for example, stiffness, toughness, extractable content,environmental stress crack resistance, and heat sealing, among otherproperties. The composition distribution of a polyolefin may be readilymeasured by methods known in the art, for example, Temperature RaisingElution Fractionation (TREF) or Crystallization Analysis Fractionation(CRYSTAF).

It is generally known in the art that a polyolefin's compositiondistribution is largely dictated by the type of catalyst used and istypically invariable for a given catalyst system. Ziegler-Nattacatalysts and chromium based catalysts produce resins with broadcomposition distributions (BCD), whereas metallocene catalysts normallyproduce resins with narrow composition distributions (NCD).

In addition to short chain branching, as discussed above, polymercatalysts often generate polymers that have long chain branching. Longchain branching may be useful in some applications, for example,contributing to polymer alignment in processing, which can make thepolymer tougher. However, the alignment can also create problems, suchas anisotropy in polymer properties. Accordingly, control over longchain branching would be useful.

SUMMARY

An exemplary embodiment described herein provides a method ofpolymerizing olefins to produce a polyolefin polymer with control overlong chain branching, including contacting ethylene and a comonomer witha catalyst system, wherein the catalyst system includes a catalystcompound comprising:

In this formula, R¹ is a saturated hydrocarbyl group of at least twocarbons in length. R² is an H, a hydrocarbyl group, a substitutedhydrocarbyl group, a heteroatom group, or connects to R³ through a ringstructure. R³ is an H, a hydrocarbyl group, a substituted hydrocarbylgroup, a heteroatom group, or connects to R² through a ring structure.R⁴ is an H or a methyl group. R⁵ is an H, a hydrocarbyl group, asubstituted hydrocarbyl group, a heteroatom group, or forms a ringstructure with R⁶. R⁶ is an H, a hydrocarbyl group, a substitutedhydrocarbyl group, a heteroatom group, or forms a ring structure withR⁵. Each R⁷ is independently an H, a hydrocarbyl group, a substitutedhydrocarbyl group, a heteroatom group, or connects to an adjacent R⁷group through a ring structure. Each X is independently a leaving groupselected from a halogen, a labile hydrocarbyl, a substitutedhydrocarbyl, a heteroatom group, or a divalent radical that links to anR², R³, or R⁷ group.

Another exemplary embodiment provides a catalyst composition comprisinga catalyst compound supported to form a supported catalyst system,wherein the catalyst compound includes:

In this formula, R¹ is a saturated hydrocarbyl group of at least twocarbons in length. R² is an H, a hydrocarbyl group, a substitutedhydrocarbyl group, a heteroatom group, or connects to R³ through a ringstructure. R³ is an H, a hydrocarbyl group, a substituted hydrocarbylgroup, a heteroatom group, or connects to R² through a ring structure.R⁴ is an H or a methyl group. R⁵ is an H, a hydrocarbyl group, asubstituted hydrocarbyl group, a heteroatom group, or forms a ringstructure with R⁶. R⁶ is an H, a hydrocarbyl group, a substitutedhydrocarbyl group, a heteroatom group, or forms a ring structure withR⁵. Each R⁷ is independently an H, a hydrocarbyl group, a substitutedhydrocarbyl group, a heteroatom group, or connects to an adjacent R⁷group through a ring structure. Each X is independently a leaving groupselected from a halogen, a labile hydrocarbyl, a substitutedhydrocarbyl, a heteroatom group, or a divalent radical that links to anR², R³, or R⁷ group.

Another embodiment provides a polymer formed from a catalyst compoundsupported to form a supported catalyst system, wherein the catalystcompound includes:

In this formula, R¹ is a saturated hydrocarbyl group of at least twocarbons in length. R² is an H, a hydrocarbyl group, a substitutedhydrocarbyl group, a heteroatom group, or connects to R³ through a ringstructure. R³ is an H, a hydrocarbyl group, a substituted hydrocarbylgroup, a heteroatom group, or connects to R² through a ring structure.R⁴ is an H or a methyl group. R⁵ is an H, a hydrocarbyl group, asubstituted hydrocarbyl group, a heteroatom group, or forms a ringstructure with R⁶. R⁶ is an H, a hydrocarbyl group, a substitutedhydrocarbyl group, a heteroatom group, or forms a ring structure withR⁵. Each R⁷ is independently an H, a hydrocarbyl group, a substitutedhydrocarbyl group, a heteroatom group, or connects to an adjacent R⁷group through a ring structure. Each X is independently a leaving groupselected from a halogen, a labile hydrocarbyl, a substitutedhydrocarbyl, a heteroatom group, or a divalent radical that links to anR², R³, or R⁷ group.

DETAILED DESCRIPTION

FIG. 1 is a graph of shear viscosity for polymers produced by the testcatalysts versus the control polymers.

FIG. 2 is a graph of elongation viscosity for polymers produced by thetest catalysts versus the control polymers.

FIG. 3 is a graph of melt strength for polymers produced by the testcatalysts versus the control polymers.

FIG. 4 is a comparative chart showing the values used to produce a 1 milfilm of the two test polymers versus a control.

FIG. 5 is a comparative chart of physical properties for 1-mil (25.4 μm)films made from the test polymers and compared to an Enable resin usingExceed as a control.

FIG. 6 is a graph showing that the polymers made by the test catalystshave heat seal properties similar to those of the Exceed control.

FIG. 7 is a comparative chart of physical properties for 2-mil (50.8 μm)films made from the test polymers and compared to an Enable resin, usingExceed as a control.

FIG. 8 is a graph showing that the polymers made by the test catalystshave heat seal properties similar to those of the Exceed control.

DETAILED DESCRIPTION

It has been discovered that bridged hafnocenes having a 3-propylsubstituant are highly active on supports and appear to produce linearlow density polyethylene with low or undetectable long chain branching.In addition, the comonomer (C6) incorporation is flat to slightlyfavoring a broad orthogonal composition distribution (BOCD). Theseproperties provide attractive properties for films produced with thisresin.

In lab testing an exemplary hafnocene(Me₂Si(3-n-propyl-η⁵-Cp)(η⁵-CpMe₄)HfMe₂) (catalyst A) was supported onSMAO and run in a gas phase batch reactor, producing linear low densitypolyethylene (LLDPE) with activity of about 8000 g/g. Tests using crossfractionation chromatography (CFC) graph indicated a substantially flatcomonomer distribution.

Rheology data for polymer produced with catalyst A was compared to acontrol polymer, Exceed® 1018 from ExxonMobil®, which is a commercialLLDPE resin. The data on the lab scale resins indicated that the polymerhas no LCB which has been shown to deteriorate both toughness (dart) andtear properties in blown films.

Similar hafnocenes were expected to produce similar resins. To testthis, catalyst A was used to produce a larger amount of resin at a pilotplant scale. Further, another catalyst,[(2-Me-3-n-Pr-η⁵-Indenyl)-SiMe₂-(η⁵-CpMe₄)]HfMe₂, hereinafter “catalystB”, was also used to produce resin at the pilot plant scale. Asdiscussed in the examples below, the resins produced by these catalystswere processed into blown film. The measured properties indicated thatboth catalysts produced resins with low long chain branching (LCB).

It is believed that a significant amount of the control over the LCB maybe achieved, for example, by the n-alkyl substituent. Manipulation ofthe other ligands and bridges would allow for control of MW, commonerincorporation and activity. This may be achieved by a catalyst havingthe general structure shown in formula (I).

In formula (I), R¹ is a saturated hydrocarbyl group of at least twocarbons in length. R² is an H, a hydrocarbyl group, a substitutedhydrocarbyl group, a heteroatom group, or connects to R³ through a ringstructure. R³ is an H, a hydrocarbyl group, a substituted hydrocarbylgroup, a heteroatom group, or connects to R² through a ring structure.R⁴ is an H or a methyl group. R⁵ is an H, a hydrocarbyl group, asubstituted hydrocarbyl group, a heteroatom group, or forms a ringstructure with R⁶. R⁶ is an H, a hydrocarbyl group, a substitutedhydrocarbyl group, a heteroatom group, or forms a ring structure withR⁵. Each R⁷ is independently an H, a hydrocarbyl group, a substitutedhydrocarbyl group, a heteroatom group, or connects to an adjacent R⁷group through a ring structure. Each X is independently a leaving groupselected from a halogen, a labile hydrocarbyl, a substitutedhydrocarbyl, a heteroatom group, or a divalent radical that links to anR², R³, or R⁷ group. These catalysts can be used in single catalystsystems, or in cocatalyst systems using other metallocenes or catalysts,as discussed below.

Catalyst Compounds

Metallocene Catalyst Compounds

Metallocene catalyst compounds can include “half sandwich” and/or “fullsandwich” compounds having one or more Cp ligands (cyclopentadienyl andligands isolobal to cyclopentadienyl) bound to at least one Group 3 toGroup 12 metal atom, and one or more leaving groups bound to the atleast one metal atom. As used herein, all reference to the PeriodicTable of the Elements and groups thereof is to the NEW NOTATIONpublished in HAWLEY'S CONDENSED CHEMICAL DICTIONARY, Thirteenth Edition,John Wiley & Sons, Inc., (1997) (reproduced there with permission fromIUPAC), unless reference is made to the Previous IUPAC form noted withRoman numerals (also appearing in the same), or unless otherwise noted.

The Cp ligands are one or more rings or ring systems, at least a portionof which includes π-bonded systems, such as cycloalkadienyl ligands andheterocyclic analogues. The rings or ring systems typically includeatoms selected from the group consisting of Groups 13 to 16 atoms, and,in a particular exemplary embodiment, the atoms that make up the Cpligands are selected from the group consisting of carbon, nitrogen,oxygen, silicon, sulfur, phosphorous, germanium, boron, aluminum, andcombinations thereof, where carbon makes up at least 50% of the ringmembers. In a more particular exemplary embodiment, the Cp ligands areselected from the group consisting of substituted and unsubstitutedcyclopentadienyl ligands and ligands isolobal to cyclopentadienyl,non-limiting examples of which include cyclopentadienyl, indenyl,fluorenyl and other structures. Further non-limiting examples of suchligands include cyclopentadienyl, cyclopentaphenanthreneyl, indenyl,benzindenyl, fluorenyl, octahydrofluorenyl, cyclooctatetraenyl,cyclopentacyclododecene, phenanthrindenyl, 3,4-benzofluorenyl,9-phenylfluorenyl, 8-H-cyclopent[a]acenaphthylenyl,7-H-dibenzofluorenyl, indeno[1,2-9]anthrene, thiophenoindenyl,thiophenofluorenyl, hydrogenated versions thereof (e.g.,4,5,6,7-tetrahydroindenyl, or “H₄ Ind”), substituted versions thereof(as discussed and described in more detail below), and heterocyclicversions thereof.

The metal atom “M” of the metallocene catalyst compound can be selectedfrom the group consisting of Groups 3 through 12 atoms and lanthanideGroup atoms in one exemplary embodiment; and selected from the groupconsisting of Groups 3 through 10 atoms in a more particular exemplaryembodiment, and selected from the group consisting of Sc, Ti, Zr, Hf, V,Nb, Ta, Mn, Re, Fe, Ru, Os, Co, Rh, Ir, and Ni in yet a more particularexemplary embodiment; and selected from the group consisting of Groups4, 5, and 6 atoms in yet a more particular exemplary embodiment, and Ti,Zr, Hf atoms in yet a more particular exemplary embodiment, and Hf inyet a more particular exemplary embodiment. The oxidation state of themetal atom “M” can range from 0 to +7 in one exemplary embodiment; andin a more particular exemplary embodiment, can be +1, +2, +3, +4, or +5;and in yet a more particular exemplary embodiment can be +2, +3 or +4.The groups bound to the metal atom “M” are such that the compoundsdescribed below in the formulas and structures are electrically neutral,unless otherwise indicated. The Cp ligand forms at least one chemicalbond with the metal atom M to form the “metallocene catalyst compound.”The Cp ligands are distinct from the leaving groups bound to thecatalyst compound in that they are not highly susceptible tosubstitution/abstraction reactions.

The one or more metallocene catalyst compounds can be represented by theformula (I):

Cp^(A)Cp^(B)MX_(n)   (I)

in which M is as described above; each X is chemically bonded to M; eachCp group is chemically bonded to M; and n is 0 or an integer from 1 to4, and either 1 or 2 in a particular exemplary embodiment.

The ligands represented by Cp^(A) and Cp^(B) in formula (I) can be thesame or different cyclopentadienyl ligands or ligands isolobal tocyclopentadienyl, either or both of which can contain heteroatoms andeither or both of which can be substituted by a group R. In at least onespecific embodiment, Cp^(A) and Cp^(B) are independently selected fromthe group consisting of cyclopentadienyl, indenyl, tetrahydroindenyl,fluorenyl, and substituted derivatives of each.

Independently, each Cp^(A) and Cp^(B) of formula (I) can beunsubstituted or substituted with any one or combination of substituentgroups R. Non-limiting examples of substituent groups R as used instructure (I) as well as ring substituents in structures Va-d, discussedand described below, include groups selected from the group consistingof hydrogen radicals, alkyls, alkenyls, alkynyls, cycloalkyls, aryls,acyls, aroyls, alkoxys, aryloxys, alkylthiols, dialkylamines,alkylamidos, alkoxycarbonyls, aryloxycarbonyls, carbamoyls, alkyl- anddialkyl-carbamoyls, acyloxys, acylaminos, aroylaminos, and combinationsthereof. More particular non-limiting examples of alkyl substituents Rassociated with formulas (I) through (Va-d) include methyl, ethyl,propyl, butyl, pentyl, hexyl, cyclopentyl, cyclohexyl, benzyl, phenyl,methylphenyl, and tert-butylphenyl groups and the like, including alltheir isomers, for example, tertiary-butyl, isopropyl, and the like.Other possible radicals include substituted alkyls and aryls such as,for example, fluoromethyl, fluroethyl, difluroethyl, iodopropyl,bromohexyl, chlorobenzyl, hydrocarbyl substituted organometalloidradicals including trimethylsilyl, trimethylgermyl, methyldiethylsilyl,and the like, and halocarbyl-substituted organometalloid radicals,including tris(trifluoromethyl)silyl, methylbis(difluoromethyl)silyl,bromomethyldimethylgermyl and the like; and disubstituted boron radicalsincluding dimethylboron, for example; and disubstituted Group 15radicals including dimethylamine, dimethylphosphine, diphenylamine,methylphenylphosphine, as well as Group 16 radicals including methoxy,ethoxy, propoxy, phenoxy, methylsulfide, and ethylsulfide. Othersubstituent groups R include, but are not limited to, olefins such asolefinically unsaturated substituents including vinyl-terminated ligandssuch as, for example, 3-butenyl, 2-propenyl, 5-hexenyl, and the like. Inone exemplary embodiment, at least two R groups (two adjacent R groupsin a particular exemplary embodiment) are joined to form a ringstructure having from 3 to 30 atoms selected from the group consistingof carbon, nitrogen, oxygen, phosphorous, silicon, germanium, aluminum,boron, and combinations thereof. Also, a substituent group R such as1-butanyl can form a bonding association to the element M.

Each X in the formula (I) above and for the formulas, or structures,(II) through (Va-d) below is independently selected from the groupconsisting of: any leaving group, in one exemplary embodiment; halogenions, hydrides, C₁ to C₁₂ alkyls, C₂ to C₁₂ alkenyls, C₆ to C₁₂ aryls,C₇ to C₂₀ alkylaryls, C₁ to C₁₂ alkoxys, C₆ to C₁₆ aryloxys, C₇ to C₈alkylaryloxys, C₁ to C₁₂ fluoroalkyls, C₆ to C₁₂ fluoroaryls, and C₁ toC₁₂ heteroatom-containing hydrocarbons and substituted derivativesthereof, in a more particular exemplary embodiment; hydride, halogenions, C₁ to C₆ alkyls, C₂ to C₆ alkenyls, C₇ to C₁₈ alkylaryls, C₁ to C₆alkoxys, C₆ to C₁₄ aryloxys, C₇ to C₁₆ alkylaryloxys, C₁ to C₆alkylcarboxylates, C₁ to C₆ fluorinated alkylcarboxylates, C₆ to C₁₂arylcarboxylates, C₇ to C₁₈ alkylarylcarboxylates, C₁ to C₆fluoroalkyls, C₂ to C₆ fluoroalkenyls, and C₇ to C₁₈ fluoroalkylaryls inyet a more particular exemplary embodiment; hydride, chloride, fluoride,methyl, phenyl, phenoxy, benzoxy, tosyl, fluoromethyls andfluorophenyls, in yet a more particular exemplary embodiment; C₁ to C₁₂alkyls, C₂ to C₁₂ alkenyls, C₆ to C₁₂ aryls, C₇ to C₂₀ alkylaryls,substituted C₁ to C₁₂ alkyls, substituted C₆ to C₁₂ aryls, substitutedC₇ to C₂₀ alkylaryls and C₁ to C₁₂ heteroatom-containing alkyls, C₁ toC₁₂ heteroatom-containing aryls, and C₁ to C₁₂ heteroatom-containingalkylaryls, in yet a more particular exemplary embodiment; chloride,fluoride, C₁ to C₆ alkyls, C₂ to C₆ alkenyls, C₇ to C₁₈ alkylaryls,halogenated C₁ to C₆ alkyls, halogenated C₂ to C₆ alkenyls, andhalogenated C₇ to C₁₈ alkylaryls, in yet a more particular exemplaryembodiment; fluoride, methyl, ethyl, propyl, phenyl, methylphenyl,dimethylphenyl, trimethylphenyl, fluoromethyls (mono-, di- andtrifluoromethyls) and fluorophenyls (mono-, di-, tri-, tetra- andpentafluorophenyls), in yet a more particular exemplary embodiment; andfluoride, in yet a more particular exemplary embodiment.

Other non-limiting examples of X groups include amines, phosphines,ethers, carboxylates, dienes, hydrocarbon radicals having from 1 to 20carbon atoms, fluorinated hydrocarbon radicals (e.g., —C₆F₅(pentafluorophenyl)), fluorinated alkylcarboxylates (e.g., CF₃C(O)O⁻),hydrides, halogen ions and combinations thereof. Other examples of Xligands include alkyl groups such as cyclobutyl, cyclohexyl, methyl,heptyl, tolyl, trifluoromethyl, tetramethylene, pentamethylene,methylidene, methyoxy, ethyoxy, propoxy, phenoxy, bis(N-methylanilide),dimethylamide, dimethylphosphide radicals and the like. In one exemplaryembodiment, two or more Xs form a part of a fused ring or ring system.In at least one specific embodiment, X can be a leaving group selectedfrom the group consisting of chloride ions, bromide ions, C₁ to C₁₀alkyls, and C₂ to C₁₂ alkenyls, carboxylates, acetylacetonates, andalkoxides.

The metallocene catalyst compound includes those of formula (I) whereCp^(A) and Cp^(B) are bridged to each other by at least one bridginggroup, (A), such that the structure is represented by formula (II):

Cp^(A)(A)Cp^(B)MX_(n)   (II)

These bridged compounds represented by formula (II) are known as“bridged metallocenes.” The elements Cp^(A), Cp^(B), M, X and n informula (II) are as defined above for formula (I); where each Cp ligandis chemically bonded to M, and (A) is chemically bonded to each Cp. Thebridging group (A) can include divalent hydrocarbon groups containing atleast one Group 13 to 16 atom, such as, but not limited to, at least oneof a carbon, oxygen, nitrogen, silicon, aluminum, boron, germanium, tinatom, and combinations thereof; where the heteroatom can also be C₁ toC₁₂ alkyl or aryl substituted to satisfy neutral valency. In at leastone specific embodiment, the bridging group (A) can also includesubstituent groups R as defined above (for formula (I)) includinghalogen radicals and iron. In at least one specific embodiment, thebridging group (A) can be represented by C₁ to C₆ alkylenes, substitutedC₁ to C₆ alkylenes, oxygen, sulfur, R′₂C═, R′₂Si═, ═Si(R′)₂Si(R′₂)═,R′₂Ge═, and R′P═, where “═” represents two chemical bonds, R′ isindependently selected from the group consisting of hydride,hydrocarbyl, substituted hydrocarbyl, halocarbyl, substitutedhalocarbyl, hydrocarbyl-substituted organometalloid,halocarbyl-substituted organometalloid, disubstituted boron,disubstituted Group 15 atoms, substituted Group 16 atoms, and halogenradical; and where two or more R′ can be joined to form a ring or ringsystem. In at least one specific embodiment, the bridged metallocenecatalyst compound of formula (II) includes two or more bridging groups(A). In one or more embodiments, (A) can be a divalent bridging groupbound to both Cp^(A) and Cp^(B) selected from the group consisting ofdivalent C₁ to C₂₀ hydrocarbyls and C₁ to C₂₀ heteroatom containinghydrocarbonyls, where the heteroatom containing hydrocarbonyls includefrom one to three heteroatoms.

The bridging group (A) can include methylene, ethylene, ethylidene,propylidene, isopropylidene, diphenylmethylene, 1,2-dimethylethylene,1,2-diphenylethylene, 1,1,2,2-tetramethylethylene, dimethylsilyl,diethylsilyl, methyl-ethylsilyl, trifluoromethylbutylsilyl,bis(trifluoromethyl)silyl, di(n-butyl)silyl, di(n-propyl)silyl,di(i-propyl)silyl, di(n-hexyl)silyl, dicyclohexylsilyl, diphenylsilyl,cyclohexylphenylsilyl, t-butylcyclohexylsilyl, di(t-butylphenyl)silyl,di(p-tolyl)silyl and the corresponding moieties where the Si atom isreplaced by a Ge or a C atom; as well as dimethylsilyl, diethylsilyl,dimethylgermyl and diethylgermyl.

The bridging group (A) can also be cyclic, having, for example, 4 to 10ring members; in a more particular exemplary embodiment, bridging group(A) can have 5 to 7 ring members. The ring members can be selected fromthe elements mentioned above, and, in a particular embodiment, can beselected from one or more of B, C, Si, Ge, N, and O. Non-limitingexamples of ring structures which can be present as, or as part of, thebridging moiety are cyclobutylidene, cyclopentylidene, cyclohexylidene,cycloheptylidene, cyclooctylidene and the corresponding rings where oneor two carbon atoms are replaced by at least one of Si, Ge, N and O. Inone or more embodiments, one or two carbon atoms can be replaced by atleast one of Si and Ge. The bonding arrangement between the ring and theCp groups can be cis-, trans-, or a combination thereof.

The cyclic bridging groups (A) can be saturated or unsaturated and/orcan carry one or more substituents and/or can be fused to one or moreother ring structures. If present, the one or more substituents can be,in at least one specific embodiment, selected from the group consistingof hydrocarbyl (e.g., alkyl, such as methyl) and halogen (e.g., F, Cl).The one or more Cp groups to which the above cyclic bridging moietiescan optionally be fused can be saturated or unsaturated, and areselected from the group consisting of those having 4 to 10, moreparticularly 5, 6, or 7 ring members (selected from the group consistingof C, N, O, and S in a particular exemplary embodiment) such as, forexample, cyclopentyl, cyclohexyl and phenyl. Moreover, these ringstructures can themselves be fused such as, for example, in the case ofa naphthyl group. Moreover, these (optionally fused) ring structures cancarry one or more substituents. Illustrative, non-limiting examples ofthese substituents are hydrocarbyl (particularly alkyl) groups andhalogen atoms. The ligands C_(P) ^(A) and Cp^(B) of formula (I) and (II)can be different from each other. The ligands C_(P) ^(A) and Cp^(B) offormula (I) and (II) can be the same. The metallocene catalyst compoundcan include bridged mono-ligand metallocene compounds (e.g., monocyclopentadienyl catalyst components).

It is contemplated that the metallocene catalyst components discussedand described above include their structural or optical or enantiomericisomers (racemic mixture), and, in one exemplary embodiment, can be apure enantiomer. As used herein, a single, bridged, asymmetricallysubstituted metallocene catalyst compound having a racemic and/or mesoisomer does not, itself, constitute at least two different bridged,metallocene catalyst components.

The amount of the transition metal component of the one or moremetallocene catalyst compounds in the catalyst system can range from alow of about 0.2 wt. %, about 3 wt. %, about 0.5 wt. %, or about 0.7 wt.% to a high of about 1 wt. %, about 2 wt. %, about 2.5 wt. %, about 3wt. %, about 3.5 wt. %, or about 4 wt. %, based on the total weight ofthe catalyst system.

Other metallocene catalyst compounds that may be used are supportedconstrained geometry catalysts (sCGC) that include (a) an ionic complex,(b) a transition metal compound, (c) an organometal compound, and (d) asupport material. In some embodiments, the sCGC catalyst may include aborate ion. The borate anion is represented by the formula[BQ_(4-z′)(G_(q)(T-H)_(r))_(z′)]^(d−), wherein: B is boron in a valencestate of 3; Q is selected from the group consisting of hydride,dihydrocarbylamido, halide, hydrocarbyloxide, hydrocarbyl, andsubstituted-hydrocarbyl radicals; z′ is an integer in a range from 1 to4; G is a polyvalent hydrocarbon radical having r+1 valencies bonded toM′ and r groups (T-H); q is an integer, 0 or 1; the group (T-H) is aradical wherein T includes O, S, NR, or PR, the O, S, N or P atom ofwhich is bonded to hydrogen atom H, wherein R is a hydrocarbyl radical,a trihydrocarbylsilyl radical, a trihydrocarbyl germyl radical orhydrogen; r is an integer from 1 to 3; and d is 1. Alternatively theborate ion may be representative by the formula[BQ_(4-z′)(G_(q)(T-M^(o)R^(C) _(x-1)X^(a) _(y))_(r))_(z′)]^(d−),wherein: B is boron in a valence state of 3; Q is selected from thegroup consisting of hydride, dihydrocarbylamido, halide,hydrocarbyloxide, hydrocarbyl, and substituted-hydrocarbyl radicals; z′is an integer in a range from 1 to 4; G is a polyvalent hydrocarbonradical having r+1 valencies bonded to B and r groups (T-M^(o)R^(C)_(x-1)X^(a) _(y)); q is an integer, 0 or 1; the group (T-M^(o)R^(C)_(x-1)X^(a) _(y)) is a radical wherein T includes O, S, NR, or PR, theO, S, N or P atom of which is bonded to M^(o), wherein R is ahydrocarbyl radical, a trihydrocarbylsilyl radical, a trihydrocarbylgermyl radical or hydrogen; M^(o) is a metal or metalloid selected fromGroups 1-14 of the Periodic Table of the Elements, R^(C) independentlyeach occurrence is hydrogen or a group having from 1 to 80 nonhydrogenatoms which is hydrocarbyl, hydrocarbylsilyl, orhydrocarbylsilylhydrocarbyl; X^(a) is a noninterfering group having from1 to 100 nonhydrogen atoms which is halo-substituted hydrocarbyl,hydrocarbylamino-substituted hydrocarbyl, hydrocarbyloxy-substitutedhydrocarbyl, hydrocarbylamino, di(hydrocarbyl)amino, hydrocarbyloxy orhalide; x is a nonzero integer which may range from 1 to an integerequal to the valence of M^(o); y is zero or a nonzero integer which mayrange from 1 to an integer equal to 1 less than the valence of M^(o);and x+y equals the valence of M^(o); r is an integer from 1 to 3; and dis 1. In some embodiments, the borate ion may be of the above describedformulas where z′ is 1 or 2, q is 1, and r is 1.

The catalyst system can include other single site catalysts such asGroup 15-containing catalysts. The catalyst system can include one ormore second catalysts in addition to the single site catalyst compoundsuch as chromium-based catalysts, Ziegler-Natta catalysts, one or moreadditional single-site catalysts such as metallocenes or Group15-containing catalysts, bimetallic catalysts, and mixed catalysts. Thecatalyst system can also include AlCl₃, cobalt, iron, palladium, or anycombination thereof.

The metallocene catalyst compound can include any catalyst orcombinations of catalysts discussed and described herein. For example,the metallocene catalyst compound can include, but is not limited to,Me₂Si(3-n-propyl-η⁵-Cp)(η⁵-CpMe₄)HfMe₂ (catalyst A),[(2-Me-3-n-propyl-η⁵-Indenyl)-SiMe₂-(η⁵-CpMe₄)]HfMe₂ (catalyst B), orany other catalyst compounds mentioned herein. The structural formulafor these catalysts is:

Catalyst Slurry

The catalyst system may include a catalyst or catalyst component in aslurry, which may have a single catalyst compound, or may have addedcatalyst components that are added as a solution to the slurry orcosupported on the support. Any number of combinations of catalystcomponents may be used in embodiments. For example, the catalystcomponent slurry can include an activator and a support, or a supportedactivator. Further, the slurry can include a catalyst compound inaddition to the activator and the support. As noted, the catalystcompound in the slurry may be supported.

The slurry may include one or more activators and supports, and one morecatalyst compounds. For example, the slurry may include two or moreactivators (such as alumoxane and a modified alumoxane) and a catalystcompound, or the slurry may include a supported activator and more thanone catalyst compounds. In one embodiment, the slurry includes asupport, an activator, and a catalyst compound. In another embodimentthe slurry includes a support, an activator and two different catalystcompounds, which may be added to the slurry separately or incombination. The slurry, containing silica and alumoxane, may becontacted with a catalyst compound, allowed to react, and thereafter theslurry is contacted with another catalyst compound, for example, in atrim system.

The molar ratio of metal in the activator, such as aluminum, ormetalloid, such as boron, to metal in the catalyst compound in theslurry may be 1000:1 to 0.5:1, 300:1 to 1:1, or 150:1 to 1:1. The slurrycan include a support material which may be any inert particulatecarrier material known in the art, including, but not limited to,silica, fumed silica, alumina, clay, talc or other support materialssuch as disclosed above. In one embodiment, the slurry contains silicaand an activator, such as methyl aluminoxane (“MAO”), modified methylaluminoxane (“MMAO”), as discussed further below.

One or more diluents or carriers can be used to facilitate thecombination of any two or more components of the catalyst system in theslurry or in the trim catalyst solution. For example, the single sitecatalyst compound and the activator can be combined together in thepresence of toluene or another non-reactive hydrocarbon or hydrocarbonmixture to provide the catalyst mixture. In addition to toluene, othersuitable diluents can include, but are not limited to, ethylbenzene,xylene, pentane, hexane, heptane, octane, other hydrocarbons, or anycombination thereof. The support, either dry or mixed with toluene canthen be added to the catalyst mixture or the catalyst/activator mixturecan be added to the support.

Catalyst Supports

As used herein, the terms “support” and “carrier” are usedinterchangeably and refer to any support material, including a poroussupport material, such as talc, inorganic oxides, and inorganicchlorides. The one or more single site catalyst compounds of the slurrycan be supported on the same or separate supports together with theactivator, or the activator can be used in an unsupported form, or canbe deposited on a support different from the single site catalystcompounds, or any combination thereof. This may be accomplished by anytechnique commonly used in the art. There are various other methods inthe art for supporting a single site catalyst compound. For example, thesingle site catalyst compound can contain a polymer bound ligand. Thesingle site catalyst compounds of the slurry can be spray dried. Thesupport used with the single site catalyst compound can befunctionalized.

The support can be or include one or more inorganic oxides, for example,of Group 2, 3, 4, 5, 13, or 14 elements. The inorganic oxide caninclude, but is not limited to silica, alumina, titania, zirconia,boria, zinc oxide, magnesia, or any combination thereof. Illustrativecombinations of inorganic oxides can include, but are not limited to,alumina-silica, silica-titania, alumina-silica-titania,alumina-zirconia, alumina-titania, and the like. The support can be orinclude alumina, silica, or a combination thereof. In one embodimentdescribed herein, the support is silica.

Suitable commercially available silica supports can include, but are notlimited to, ES757, ES70, and ES70W available from PQ Corporation.Suitable commercially available silica-alumina supports can include, butare not limited to, SIRAL® 1, SIRAL® 5, SIRAL® 10, SIRAL® 20, SIRAL®28M, SIRAL® 30, and SIRAL® 40, available from SASOL®. Generally,catalysts supports comprising silica gels with activators, such asmethylaluminoxanes (MAOs), are used in the trim systems described, sincethese supports may function better for co-supporting solution carriedcatalysts. Suitable supports may also be selected from the Cab-o-sil®materials available from Cabot Corporation and silica materialsavailable from the Grace division of W.R. Grace & Company.

Catalyst supports may also include polymers that are covalently bondedto a ligand on the catalyst. For example, two or more catalyst moleculesmay be bonded to a single polyolefin chain.

Catalyst Activators

As used herein, the term “activator” may refer to any compound orcombination of compounds, supported, or unsupported, which can activatea single site catalyst compound or component, such as by creating acationic species of the catalyst component. For example, this caninclude the abstraction of at least one leaving group (the “X” group inthe single site catalyst compounds described herein) from the metalcenter of the single site catalyst compound or component. The activatormay also be referred to as a “co-catalyst”.

For example, the activator can include a Lewis acid or anon-coordinating ionic activator or ionizing activator, or any othercompound including Lewis bases, aluminum alkyls, and/orconventional-type co-catalysts. In addition to methylaluminoxane (“MAO”)and modified methylaluminoxane (“MMAO”) mentioned above, illustrativeactivators can include, but are not limited to, aluminoxane or modifiedaluminoxane, and/or ionizing compounds, neutral or ionic, such asDimethylanilinium tetrakis(pentafluorophenyl)borate, Triphenylcarbeniumtetrakis(pentafluorophenyl)borate, Dimethylaniliniumtetrakis(3,5-(CF₃)₂phenyl)borate, Triphenylcarbeniumtetrakis(3,5-(CF₃)₂phenyOborate, Dimethylaniliniumtetrakis(perfluoronapthyl)borate, Triphenylcarbeniumtetrakis(perfluoronapthyl)borate, Dimethylaniliniumtetrakis(pentafluorophenyl)aluminate, Triphenylcarbeniumtetrakis(pentafluorophenyl)aluminate, Dimethylaniliniumtetrakis(perfluoronapthyl)aluminate, Triphenylcarbeniumtetrakis(perfluoronapthyl)aluminate, a tris(perfluorophenyl)boron, atris(perfluoronaphthyl)boron, tris(perfluorophenyl)aluminum, atris(perfluoronaphthyl)aluminum or any combinations thereof.

It is recognized that these activators may bind directly to the supportsurface or be modified to allow them to be bound to a support surfacewhile still maintaining their compatability with the polymerizationsystem. Such tethering agents may be derived from groups that arereactive with surface hydroxyl species. Non-limiting examples ofreactive functional groups that can be used to create tethers includealuminum halides, aluminum hydrides, aluminum alkyls, aluminum aryls,sluminum alkoxides, electrophilic silicon reagents, alkoxy silanes,amino silanes, boranes.

Aluminoxanes can be described as oligomeric aluminum compounds having—Al(R)—O— subunits, where R is an alkyl group. Examples of aluminoxanesinclude, but are not limited to, methylaluminoxane (“MAO”), modifiedmethylaluminoxane (“MMAO”), ethylaluminoxane, isobutylaluminoxane, or acombination thereof. Aluminoxanes can be produced by the hydrolysis ofthe respective trialkylaluminum compound. MMAO can be produced by thehydrolysis of trimethylaluminum and a higher trialkylaluminum, such astriisobutylaluminum. MMAOs are generally more soluble in aliphaticsolvents and more stable during storage. There are a variety of methodsfor preparing aluminoxane and modified aluminoxanes.

In one or more embodiments, a visually clear MAO can be used. Forexample, a cloudy or gelled aluminoxane can be filtered to produce aclear aluminoxane or clear aluminoxane can be decanted from a cloudyaluminoxane solution. In another embodiment, a cloudy and/or gelledaluminoxane can be used. Another aluminoxane can include a modifiedmethyl aluminoxane (“MMAO”) type 3A (commercially available from AkzoChemicals, Inc. under the trade name Modified Methylaluminoxane type 3A,discussed and described in U.S. Pat. No. 5,041,584). A suitable sourceof MAO can be a solution having from about 1 wt. % to about a 50 wt. %MAO, for example. Commercially available MAO solutions can include the10 wt. % and 30 wt. % MAO solutions available from AlbemarleCorporation, of Baton Rouge, La.

As noted above, one or more organo-aluminum compounds such as one ormore alkylaluminum compounds can be used in conjunction with thealuminoxanes. For example, alkylaluminum species that may be used arediethylaluminum ethoxide, diethylaluminum chloride, and/ordiisobutylaluminum hydride. Examples of trialkylaluminum compoundsinclude, but are not limited to, trimethylaluminum, triethylaluminum(“TEAL”), triisobutylaluminum (“TiBAl”), tri-n-hexylaluminum,tri-n-octylaluminum, tripropylaluminum, tributylaluminum, and the like.

Continuity Additive/Static Control Agents

In gas-phase polyethylene production processes, as disclosed herein, itmay be desirable to additionally use one or more static control agentsto aid in regulating static levels in the reactor. As used herein, astatic control agent is a chemical composition which, when introducedinto a fluidized bed reactor, may influence or drive the static charge(negatively, positively, or to zero) in the fluidized bed. The specificstatic control agent used may depend upon the nature of the staticcharge, and the choice of static control agent may vary dependent uponthe polymer being produced and the single site catalyst compounds beingused.

Control agents such as aluminum stearate may be employed. The staticcontrol agent used may be selected for its ability to receive the staticcharge in the fluidized bed without adversely affecting productivity.Other suitable static control agents may also include aluminumdistearate, ethoxlated amines, and anti-static compositions such asthose provided by Innospec Inc. under the trade name OCTASTAT. Forexample, OCTASTAT 2000 is a mixture of a polysulfone copolymer, apolymeric polyamine, and oil-soluble sulfonic acid.

Any of the aforementioned control agents, as well as those described in,for example, WO 01/44322, listed under the heading Carboxylate MetalSalt and including those chemicals and compositions listed as antistaticagents may be employed either alone or in combination as a controlagent. For example, the carboxylate metal salt may be combined with anamine containing control agent (e.g., a carboxylate metal salt with anyfamily member belonging to the KEMAMINE® (available from CromptonCorporation) or ATMER® (available from ICI Americas Inc.) family ofproducts).

Other useful continuity additives include ethyleneimine additives usefulin embodiments disclosed herein may include polyethyleneimines havingthe following general formula:

—(CH₂—CH₂—NH)_(n)—

in which n may be from about 10 to about 10,000. The polyethyleneiminesmay be linear, branched, or hyperbranched (e.g., forming dendritic orarborescent polymer structures). They can be a homopolymer or copolymerof ethyleneimine or mixtures thereof (referred to aspolyethyleneimine(s) hereafter). Although linear polymers represented bythe chemical formula —[CH₂-CH₂-NH]— may be used as thepolyethyleneimine, materials having primary, secondary, and tertiarybranches can also be used. Commercial polyethyleneimine can be acompound having branches of the ethyleneimine polymer. Suitablepolyethyleneimines are commercially available from BASF Corporationunder the trade name Lupasol. These compounds can be prepared as a widerange of molecular weights and product activities. Examples ofcommercial polyethyleneimines sold by BASF suitable for use in thepresent invention include, but are not limited to, Lupasol FG andLupasol WF. Another useful continuity additive can include a mixture ofaluminum distearate and an ethoxylated amine-type compound, e.g.,IRGASTAT AS-990, available from Huntsman (formerly Ciba SpecialtyChemicals). The mixture of aluminum distearate and ethoxylated aminetype compound can be slurried in mineral oil e.g., Hydrobrite 380. Forexample, the mixture of aluminum distearate and an ethoxylated aminetype compound can be slurried in mineral oil to have total slurryconcentration of ranging from about 5 wt. % to about 50 wt. % or about10 wt. % to about 40 wt. %, or about 15 wt. % to about 30 wt. %.

The continuity additive(s) or static control agent(s) may be added tothe reactor in an amount ranging from 0.05 to 200 ppm, based on theweight of all feeds to the reactor, excluding recycle. In someembodiments, the continuity additive may be added in an amount rangingfrom 2 to 100 ppm, or in an amount ranging from 4 to 50 ppm.

Controlling Product Properties

The properties of the product polymer may be controlled by adjusting thetiming, temperature, concentrations, and sequence of the mixing of thesolution, the slurry and any optional added materials (nucleatingagents, catalyst compounds, activators, etc) described above. The MWD,composition distribution, melt index, relative amount of polymerproduced by each catalyst, and other properties of the polymer producedmay also be changed by manipulating process parameters. Any number ofprocess parameters may be adjusted, including manipulating hydrogenconcentration in the polymerization system, changing the amount of acatalyst in the polymerization system, changing the amount of a secondcatalyst in the polymerization system. Other process parameters that canbe adjusted include changing the relative ratio of the catalyst in thepolymerization process, and optionally adjusting their individual feedrates to maintain a steady or constant resin production rate. Theconcentrations of reactants in the reactor can be adjusted by changingthe amount of liquid or gas that is withdrawn or purged from theprocess, changing the amount and/or composition of a recovered liquidand/or recovered gas returned to the polymerization process, wherein therecovered liquid or recovered gas can be recovered from polymerdischarged from the polymerization process. Further concentrationparameters that can be adjusted include changing the polymerizationtemperature, changing the ethylene partial pressure in thepolymerization process, changing the ethylene to comonomer ratio in thepolymerization process, changing the activator to transition metal ratioin the activation sequence. Time dependant parameters may be adjusted,such as changing the relative feed rates of the slurry or solution,changing the mixing time, the temperature and or degree of mixing of theslurry and the solution in-line, adding different types of activatorcompounds to the polymerization process, and adding oxygen orfluorobenzene or other catalyst poison to the polymerization process.Any combinations of these adjustments may be used to control theproperties of the final polymer product.

In one embodiment, the composition distribution of the polymer productis measured at regular intervals and one of the above processparameters, such as temperature, catalyst compound feed rate, the ratioof comonomer to monomer, the monomer partial pressure, and or hydrogenconcentration, is altered to bring the composition to the desired level,if necessary. The composition distribution may be performed bytemperature rising elution fractionation (TREF), or similar techniquesTREF measures composition as a function of elution temperature.

Polymerization Process

The catalyst system can be used to polymerize one or more olefins toprovide one or more polymer products therefrom. Any suitablepolymerization process can be used, including, but not limited to, highpressure, solution, slurry, and/or gas phase polymerization processes.

The terms “polyethylene” and “polyethylene copolymer” refer to a polymerhaving at least 50 wt. % ethylene-derived units. In various embodiments,the polyethylene can have at least 70 wt. % ethylene-derived units, atleast 80 wt. % ethylene-derived units, at least 90 wt. %ethylene-derived units, at least 95 wt. % ethylene-derived units, or 100wt. % ethylene-derived units. The polyethylene can, thus, be ahomopolymer or a copolymer, including a terpolymer, having one or moreother monomeric units. As described herein, a polyethylene can include,for example, at least one or more other olefins or comonomers. Suitablecomonomers can contain 3 to 16 carbon atoms, from 3 to 12 carbon atoms,from 4 to 10 carbon atoms, and from 4 to 8 carbon atoms. Examples ofcomonomers include, but are not limited to, propylene, 1-butene,1-pentene, 1-hexene, 1-heptene, 1-octene, 4-methylpent-1-ene, 1-decene,1-dodecene, 1-hexadecene, and the like. Additionally, small amounts ofdiene monomers, such as 1,7-octadiene may be added to the polymerizationto adjust polymer properties.

The reactor temperature of a fluid bed in a gas phase polymerizationprocess can be greater than about 30° C., about 40° C., about 50° C.,about 90° C., about 100° C., about 110° C., about 120° C., about 150°C., or higher. In general, the reactor temperature is operated at thehighest feasible temperature taking into account the sinteringtemperature of the polymer product within the reactor. Preferred reactortemperatures are between 70 and 95° C. More preferred reactortemperatures are between 75 and 90° C. Thus, the upper temperature limitin one embodiment is the melting temperature of the polyethylenecopolymer produced in the reactor. However, higher temperatures mayresult in narrower MWDs, which can be improved by the addition of theMCN, or other, co-catalysts, as described herein.

Hydrogen gas can be used in olefin polymerization to control the finalproperties of the polyolefin. Using certain catalyst systems, increasingconcentrations (partial pressures) of hydrogen can increase the flowindex (FI) of the polyethylene copolymer generated. The flow index canthus be influenced by the hydrogen concentration. The amount of hydrogenin the polymerization can be expressed as a mole ratio relative to thetotal polymerizable monomer, for example, ethylene, or a blend ofethylene and hexene or propylene.

The amount of hydrogen used in the polymerization process can be anamount necessary to achieve the desired flow index of the finalpolyolefin resin. For example, the mole ratio of hydrogen to totalmonomer (Hz:monomer) can be greater than about 0.0001, greater thanabout 0.0005, or greater than about 0.001. Further, the mole ratio ofhydrogen to total monomer (Hz:monomer) can be less than about 10, lessthan about 5, less than about 3, and less than about 0.10. A desirablerange for the mole ratio of hydrogen to monomer can include anycombination of any upper mole ratio limit with any lower mole ratiolimit described herein. Expressed another way, the amount of hydrogen inthe reactor at any time can range to up to about 5,000 ppm, up to about4,000 ppm in another embodiment, up to about 3,000 ppm, or between about50 ppm and 5,000 ppm, or between about 50 ppm and 2,000 ppm in anotherembodiment. The amount of hydrogen in the reactor can range from a lowof about 1 ppm, about 50 ppm, or about 100 ppm to a high of about 400ppm, about 800 ppm, about 1,000 ppm, about 1,500 ppm, or about 2,000ppm. Further, the ratio of hydrogen to total monomer (Hz:monomer) can beabout 0.00001:1 to about 2:1, about 0.005:1 to about 1.5:1, or about0.0001:1 to about 1:1. The one or more reactor pressures in a gas phaseprocess (either single stage or two or more stages) can vary from 690kPa (100 psig) to 3,448 kPa (500 psig), in the range from 1,379 kPa (200psig) to 2,759 kPa (400 psig), or in the range from 1,724 kPa (250 psig)to 2,414 kPa (350 psig).

The gas phase reactor can be capable of producing from about 10 kg ofpolymer per hour (25 lbs/hr) to about 90,900 kg/hr (200,000 lbs/hr), orgreater, and greater than about 455 kg/hr (1,000 lbs/hr), greater thanabout 4,540 kg/hr (10,000 lbs/hr), greater than about 11,300 kg/hr(25,000 lbs/hr), greater than about 15,900 kg/hr (35,000 lbs/hr), andgreater than about 22,700 kg/hr (50,000 lbs/hr), and from about 29,000kg/hr (65,000 lbs/hr) to about 45,500 kg/hr (100,000 lbs/hr).

As noted, a slurry polymerization process can also be used inembodiments. A slurry polymerization process generally uses pressures inthe range of from about 101 kPa (1 atmosphere) to about 5,070 kPa (50atmospheres) or greater, and temperatures in the range of from about 0°C. to about 120° C., and more particularly from about 30° C. to about100° C. In a slurry polymerization, a suspension of solid, particulatepolymer can be formed in a liquid polymerization diluent medium to whichethylene, comonomers, and hydrogen along with catalyst can be added. Thesuspension including diluent can be intermittently or continuouslyremoved from the reactor where the volatile components are separatedfrom the polymer and recycled, optionally after a distillation, to thereactor. The liquid diluent employed in the polymerization medium can bean alkane having from 3 to 7 carbon atoms, such as, for example, abranched alkane. The medium employed should be liquid under theconditions of polymerization and relatively inert. When a propane mediumis used the process should be operated above the reaction diluentcritical temperature and pressure. In one embodiment, a hexane,isopentane, or isobutane medium can be employed. The slurry can becirculated in a continuous loop system.

The product polyethylene can have a melt index ratio (MIR or I₂₁/I₂)ranging from about 5 to about 300, or from about 10 to less than about150, or, in many embodiments, from about 15 to about 50. Flow index (FI,HLMI, or I₂₁ can be measured in accordance with ASTM D1238 (190° C.,21.6 kg). The melt index (MI, I₂) can be measured in accordance withASTM D1238 (at 190° C., 2.16 kg weight).

Density can be determined in accordance with ASTM D-792. Density isexpressed as grams per cubic centimeter (g/cm³) unless otherwise noted.The polyethylene can have a density ranging from a low of about 0.89g/cm³, about 0.90 g/cm³, or about 0.91 g/cm³ to a high of about 0.95g/cm³, about 0.96 g/cm³, or about 0.97 g/cm³. The polyethylene can havea bulk density, measured in accordance with ASTM D1895 method B, of fromabout 0.25 g/cm³ to about 0.5 g/cm³. For example, the bulk density ofthe polyethylene can range from a low of about 0.30 g/cm³, about 0.32g/cm³, or about 0.33 g/cm³ to a high of about 0.40 g/cm³, about 0.44g/cm³, or about 0.48 g/cm³.

The polyethylene can be suitable for such articles as films, fibers,nonwoven and/or woven fabrics, extruded articles, and/or moldedarticles. Examples of films include blown or cast films formed bycoextrusion or by lamination useful as shrink film, cling film, stretchfilm, sealing films, oriented films, snack packaging, heavy duty bags,grocery sacks, baked and frozen food packaging, medical packaging,industrial liners, membranes, etc. in food-contact and non-food contactapplications, agricultural films and sheets. Examples of fibers includemelt spinning, solution spinning and melt blown fiber operations for usein woven or non-woven form to make filters, diaper fabrics, hygieneproducts, medical garments, geotextiles, etc. Examples of extrudedarticles include tubing, medical tubing, wire and cable coatings, pipe,geomembranes, and pond liners. Examples of molded articles includesingle and multi-layered constructions in the form of bottles, tanks,large hollow articles, rigid food containers and toys, etc.

EXAMPLES

To provide a better understanding of the foregoing discussion, thefollowing non-limiting examples are provided. All parts, proportions,and percentages are by weight unless otherwise indicated.

As described herein, comonomer, such as a C₄-C₈ alpha-olefin is added toa reaction, along with ethylene monomer, to create short chain branching(SCB) in polyethylene copolymers. Without intending to be being limitedby theory, the SCB may cause a long PE chain to break free from acrystallite and be partly incorporated into other crystallites.Accordingly, polymers that have SCB on longer chains may exhibit highertoughness.

In contrast, long chain branching (LCB) are points at which two polymerchains may divide off from single polymer chains. As noted herein, LCBmay enhance toughness, but cause the polymer to more vulnerable toorientation, causing lower tear strength in the direction of extrusion.

Control of Long Chain Branching from Hafnocene Catalysts

Two catalysts were tested for the determination of long chain branchingfrom bridged systems. The catalysts have the structures shown below. Themolecular weight of catalyst A is 534 g/mol, while the molecular weightof catalyst B is 598 g/mol.

As described above, preliminary laboratory scale analysis of a resinproduced in a gas phase batch reactor from catalyst A indicated nodetectable levels of long chain branching (LCB) by melt strength (MS),gel permeation chromatography (GPC), and shear rheology. To further testwhether these types of catalysts provided control over LCB, the initialhafnocene catalyst, A, and a related hafnocene catalyst, B, were scaledup and run in in 13.5 inch pilot plant reactor, as described in theexperimental section below. Table 1 provides the reactor settings andtest results for resins produced from the pilot plant run. The polymersmade from catalysts A and B were stabilized with a commercial additivepackage and extruded using a 57 mm lab scale extruder prior to filmextrusion.

For testing, films were blown from the resins produced on a 2.5 inchscrew diameter blown film line from Gloucester Engineering (GEC) ofGloucester, Mass. The machine settings for the film blowing process ofthe 1 mil (25.4 μm) are shown in Table 2. Film was produced at twothicknesses, 1 mil (25.4 μm), and 2 mil (50.8 μm). The control extrudedback to back with the test polymers was Exceed 1018, a commercial gradeLLDPE produced by a metallocene catalyst that produces very little longchain branching. The parameters used for blowing a 1 mil film are shownin Table 2. In further studies, properties from a prior film extrusionrun of a commercial resin, Enable 2010, was added as the 2nd control.The Enable 2010 was produced at similar conditions to the other resinsexcept that the production rate was at 8 lbs/hr* inch die rather thanthe 10 lbs/hr* inch die used for the current resins. The Enable 2010 isalso an LLDPE produced by a metallocene catalyst. However, Enable 2010has significantly higher long chain branching.

FIG. 1 is a graph 100 of shear viscosity for polymers produced by thetest catalysts versus the control polymers. The x-axis 102 is thefrequency in radians/second, while the y-axis 104 is the viscosity (η)in poise (1 poise=100 millipascal second). As shown in the graph 100,the Exceed 1018 108 has the flattest curve, while Enable 2010 106 hasnearly a uniform dropoff starting at a higher value for η at a lowfrequency. Enable 2010 curve is considered an indication of LCB, e.g.,higher viscosity readings at lower frequencies. The polymers made fromthe test catalysts, catalyst B 110 and catalyst A 112, land between thecontrols, but closer in properties to the Exceed 1018 behavior,indicating low long chain branching.

FIG. 2 is a graph 200 of elongation viscosity for polymers produced bythe test catalysts versus the control polymers. The x-axis 202 is theelongation time in seconds, while the y-axis 204 is the elongationviscosity in pascals second. This measurement highlights strainhardening, which may be an indication of long chain branching. TheEnable 2010 206 has the highest values, indicating the highest longchain branching. In contrast, the Exceed 1018 has the lowest values andremains relatively flat over the entire time span, indicating minimallong chain branching. The test polymers land between the controls, withthe polymer formed from catalyst B 210 closer to the Enable 2010 206curve and the polymer formed from catalyst A 212 closer to the Exceed1018 208 curve.

FIG. 3 is a graph 300 of melt strength for polymers produced by the testcatalysts versus the control polymers. The x-axis 302 is the velocity inmillimeters per seconds, while the y-axis 304 is the melt strength inforce in centiNewtons. These plots also indicate differences due tostrain hardening, such as the break point that is indicated by thetermination of measure values along the x-axis 302. As shown in thegraph 300, the Enable 2010 306 terminates first with a relatively highMS value, which is consistent with the level of long chain branching inthe polymer. Similarly, the Exceed 1018 terminates farthest with arelatively low MS value, indicating low, or no, long chain branching.The test polymers landed between these values, with the polymer madefrom catalyst B 310 being close to the Enable 2010 306 and the polymermade from catalyst A 312 being close to Exceed 1018 308. The physicalproperties obtained from film testing also indicate the presence orabsence of long chain branching. Further, the test results may show thebenefits obtained by controlling the long chain branching. As noted, thetest results for the films are shown in Tables 3 (1 mil films) and 5 (2mil films). Comparative results, calculated as a percent differentialfrom Exceed 1018 are shown in Tables 4 and 6. As a result of thecalculation, the values for Exceed 1018 in the plots shown in FIGS. 4,5, and 7 provide a baseline at zero.

FIG. 4 is a comparative chart 400 showing the values used to produce a 1mil film of the two test polymers versus a control. The output may becontrolled by an operator, for example, at about 189 lbs/hr (86 kg/hr),allowing a comparison of the other values, such as specific output,Energy specific output, motor load and the like. The comparison mayreflect the somewhat higher long chain branching in the test polymersversus the Exceed control, although molecular weight and molecularweight distribution may also play a role.

FIG. 5 is a comparative chart 500 of physical properties for 1-mil (25.4μm) films made from the test polymers and compared to an Enable resinusing Exceed as a control. As control, the values for Exceed are also atzero in this chart 500. The differences in performance caused by longchain branching are most apparent in the anisotropy in the tear values.Long chain branching contributes to the alignment of polymer chains inthe flow or machine direction, increasing the transverse direction (TD)tear strength and decreasing the machine direction (MD) tear. This isshown by the substantial anisotropy of the Enable resin versus theExceed control. The polymer formed by test catalyst A gave values muchcloser to Exceed, while the polymer formed by catalyst B gave valuesmuch closer to those for Enable. As polymers formed from catalysts A andB have comparable MI and MIR, the anisotropy is believed to originatefrom the difference in LCB. Similarly, the dart impact strength of testpolymers land between the values of the Exceed and Enable resins, withpolymer formed from catalyst B being closer to Enable resin, indicatingits degree of LCB is greater than that of the polymer formed fromcatalyst A.

FIG. 6 is a graph showing that the polymers made by the test catalystshave heat seal properties similar to those of the Exceed control. Inthis case, the heat seal properties are dominated by density. Thepolymer formed from catalyst A has the lowest density.

FIG. 7 is a comparative chart 700 of physical properties for 2-mil (50.8μm) films made from the test polymers and compared to an Enable resin,using Exceed as a control. As control, the values for Exceed are also atzero in this chart 700. As for the 1-mil films, the differences inperformance caused by long chain branching are most apparent in theanisotropy in the tear values. In this example, the polymer formed bytest catalyst A again gave values close to Exceed. In 2-mil films, theanisotropy in the polymer was less significant, tear strength valuesobtained from polymer formed by catalyst B were still closer to thosefor the Enable control. Again, the dart impact strength of test polymersland between the values of the Exceed and Enable, with polymer formedfrom catalyst B being closer to Enable resin, indicating the its degreeof LCB may be greater than that of the polymer formed from catalyst A.FIG. 8 is a graph 800 showing that the polymers made by the testcatalysts have heat seal properties similar to those of the Exceedcontrol. It can be noted that for both the 1-mil and 2-mil films, thepolymer made from catalyst A had a lower heat sealing temperature thanthe Exceed resin. This may be due to a lower density for the polymersformed from catalyst A.

General Procedures for Forming Catalyst Components

Experimental

All manipulations were performed in an N2 purged glovebox or usingstandard Schlenk techniques. All anhydrous solvents were purchased fromSigma-Aldrich and were degassed and dried over calcined A1203 beads ormolecular sieves prior to use. Deuterated solvents were purchased fromCambridge Isotope Laboratories and were degassed and dried over aluminabeads or molecular sieves prior to use. Reagents used were purchasedfrom Sigma-Aldrich. ¹H NMR measurements were recorded on a 250MHz, 400MHz, or a 500MHz Bruker spectrometer.

Catalyst Preparations

Synthesis of Me₂Si(3-Propyl-η⁵-C₅H₃)(η⁵-Me₄C₅)HfCl₂ (catalyst A)

Me₂ClSi—Me₄C₅H (13.6 g) was dissolved in THF (200 ml) and reacted withLiC₅H₄—C₃H₇ (7.3 g) at room temperature for 15 hrs. The volatiles wereremoved in vacuo and the crude reaction mixture was extracted withhexane (2×50 ml). The extracts were filtered and reduced in vacuo (19.3g). All was dissolved in Et₂O (200 ml) and reacted with nBuLi (10.2 g 10M). The reaction was stirred for 15 hrs and filtered to collect product.The white solid was washed with hexane (60 ml) and toluene (1×80 ml,1×30ml) and dried in vacuo (18.2 g). The dilithiated ligand wasdissolved in Et₂O (200 ml) and reacted with HfCl₄ (12.5 g). The reactionwas stirred for 2 hrs and filtered through a PE frit. The residue wasextracted with Et₂O (2×40 ml) and CH₂Cl₂ (40 ml) and Et₂O (100 ml). Allfiltrates were combined, reduced in volume and cooled to −30° C. Theproduct was collected after 3 days as light yellow solid (7.8 g). Asecond crop was collected (1.1 g).

¹H NMR (400 MHz, CD₂Cl₂) δ; 6.54 (m), 5.58 (m), 5.24 (m), 2.65 (m), 2.05(s), 2.01(s), 1.98 (s), 1.92 (s), 1.55 (m), 0.91 (t), 0.81 (s), 0.78(s).

Synthesis of Supported Catalyst A

Methylalumoxane, MAO, (Albemarle, 1253 g of 10 wt % in toluene) andtoluene (358 g) were mixed together at room temperature. A solution ofcatalyst A (11.5 g) in 100 ml of toluene was added to the MAO mixtureand the crude mixture was stirred for 30 minutes. 343 g of silica(ES757, Ineos, dehydrated at 875° C.) was added to the reaction mixtureand was stirred for 1 hr at room temperature. The volatiles were removedat 75° C. in vacuo until a free flowing solid was obtained (439 g).

Synthesis of Me₂Si(2-Me,3-Propyl-η⁵-C₉H₄)(η⁵-Me₄C₅)HfCl₂ (catalyst B)

2-MeC₉H₇ (15 g) was dissolved in Et₂O (240 ml) and reacted with nBuLi (9g 10 M). After stirring for 1 hr the volatiles were removed in vacuo andthe white solid remaining was slurried in hexane (240 ml) and collectedon a frit and dried. The solid was slowly added to C₃H₇Br (115 g)dissolved in Et₂O (300 ml) and the reaction allowed to proceed for 15hrs. The volatiles were removed and the residue extracted with hexane(2×80 ml). Et₂O (100 ml) was added to the extracts and nBuLi (9 g 10 M)was added slowly. After 2 hrs the crude intermediate,2-Me,3-PropylC₉H₄Li (12.8 g) was isolated and washed with hexane (2×50ml). Me₂ClSi—Me₄C₅H (15.4 g) was dissolved in THF (200 ml) and reactedwith 12.8 g of the 2-Me,3-PropylC₉H₄Li for 1 hr. The volatiles wereremoved and the crude Me₂Si(2-Me,3-PropylC₉H₅)(Me₄C₅H) filtered over 50g silica gel (200-400 mesh) using 120 ml hexane as eluent. The volatileswere removed and the residue was dissolved in Et₂O (100 ml) and reactedwith nBuLi (16 g 10 M) for 40 hrs. The volatiles were removed and thecrude [Me₂Si(2-Me,3-PropylC₉H₄)(Me₄C₅)][Li₂] washed with hexane,slurried in Et₂O (150 ml) and reacted with HfCl₄ (17.5 g). After 2 hrsthe crude product was collected by filtration and extracted with Et₂O(3×40 ml) and CH₂Cl₂ (2×30 ml). The combined filtrates were reduced to40 ml and cooled to −30° C. A first crop (7.2 g) and a second crop (7.9g) were collected.

¹H NMR (400 MHz, CD₂Cl₂) δ; 7.64 (m), 6.45 (m), 7.26 (m), 6.88 (m), 2.78(m), 2.15 (s), 2.06 (s), 1.99 (s), 1.96 (s), 1.81 (s), 2.52 (m), 1.20(s), 1.08 (s), 0.92 (t).

Synthesis of Supported Catalyst B

Methylalumoxane, MAO, (Albemarle, 1436 g of 10 wt % in toluene) andtoluene (442 g) were mixed together at room temperature. A solution ofcatalyst B (14.8 g) in 100 ml of toluene was added to the MAO mixtureand the crude mixture was stirred for 30 minutes. 392 g of silica(ES757, Ineos, dehydrated at 875° C.) was added to the reaction mixtureand was stirred for 1 hr at room temperature. The volatiles were removedat 75° C. in vacuo until a free flowing solid was obtained (516 g).

Description of 13.25 Inch Diameter Gas-Phase Reactor

The polymerizations were conducted in a continuous gas phase fluidizedbed reactor having a straight section of 13.25 inches (33.6 cm) diameterwith a length of approximately 6.35 feet (1.94 m) and an expandedsection of 12.58 feet (3.83 m) length and 2.43 feet (0.74 m) diameter atthe largest width. The fluidized bed is made up of polymer granules, Thegaseous feed streams of ethylene and hydrogen together with liquid1-hexene were mixed together in a mixing tee arrangement and introducedbelow the reactor bed into the recycle gas line. The individual flowrates of ethylene, hydrogen and 1-hexene were controlled to maintainfixed composition targets. The ethylene concentration was controlled tomaintain a constant ethylene partial pressure. The hydrogen and 1-hexenewere controlled to maintain a constant hydrogen to ethylene mole ratioand a constant 1-hexene to ethylene mole ratio in the recirculating gas.The concentrations of all gasses were measured by an on-line gaschromatograph to ensure relatively constant composition in the recyclegas stream. The hydrogen was controlled to maintain constant hydrogen toethylene mole ratio.

The reacting bed of growing polymer particles was maintained in afluidized state by the continuous flow of the make-up feed and recyclegas through the reaction zone. A superficial gas velocity of 0.6-0.9meters/sec was used to achieve this. The fluidized bed was maintained ata constant height by withdrawing a portion of the bed at a rate equal tothe rate of formation of particulate product. The polymer productionrate was in the range of 15-25 kg/hour. The product was removedsemi-continuously via a series of valves into a fixed volume chamber.This product was purged to remove entrained hydrocarbons and treatedwith a small stream of humidified nitrogen to deactivate any tracequantities of residual catalyst. The catalyst was fed as a dry solid.The feed rate of the catalyst was adjusted for overall polymerproduction rate, while also manipulating reaction temperature and thegas compositions in the reactor. The reactor was operated at a totalpressure of about 350 psig (2413 kPa gauge). To maintain a constantfluidized bed temperature in the reactor, the temperature of the recyclegas was continuously adjusted up or down by passing the recirculatinggas through the tubes of a shell-and-tube heat exchanger with coolingwater on the shell-side to accommodate any changes in the rate of heatgeneration due to the polymerization.

A slurry mixture of anti-static agents in degassed and dried mineral oil(1:1 Aluminum stearate: N-nonyldiethanolamine at 20 wt % concentration)was fed into the reactor using a mixture of iso-pentane and nitrogen atsuch a rate as to achieve a concentration of between 38 and 123 ppmwanti-static agents in the fluidized bed. Isopentane and/or nitrogen wasoptionally employed to assist in conveying and dispersing the slurrymixture of anti-static into the reactor fluidized bed via a ⅛ inch to3/16 inch OD injection tube extending a few inches into the bed from thereactor side wall.

Physical Testing Procedures

Shear viscosity data were obtained by using a Dynamic Shear Rheometer.The temperature used was 190° C., The sample preheat period was 5 mins.All samples were stabilized and extruded prior to tests.

Elongational Viscosity data were collected at 150° C. Multiple rateswere used to characterize the polymers. Data obtained from 1 S⁻¹ werepresented in this application. All samples werer stabilized and extrudedprior to tests.

Melt Strength data were collected at 190 degree ° C. The accelerationwas 2.4 mm/s² and the piston speed was 0.265 mm/s. All samples werestabilized and extruded prior to tests.

Tensile Stength and Modulus were performed on the samples conforming toASTM D882. Tensile Strength and 1% secant Modulus were performedseparately due to rate difference. All samples were conditioned byfollowing ASTM D618 before testing

Elemndorf Tear tests were performed conforming to ASTM D1922. Allsamples were conditioned by following ASTM D618 before testing.

Dart Drop was performed by following ASTM D 1709 method A. A PhenolicDart head was used. All samples were conditioned by following ASTM D 618before testing.

Haze was performed by following ASTM D1003. All samples were conditionedby following ASTM D 618 before testing.

Gloss was performed by following ASTM D2457. All samples wereconditioned by following ASTM D618 before testing.

Cross-fractionation chromatography (CFC)

Cross-fractionation chromatography (CFC) was performed on a CFC-2instrument from Polymer Char, Valencia, Spain. The instrument wasoperated and subsequent data processing, e.g., smoothing parameters,setting baselines, and defining integration limits, was performedaccording to the manner described in the CFC User Manual provided withthe instrument or in a manner commonly used in the art. The instrumentwas equipped with a TREF column (stainless steel; o.d., ⅜″; length, 15cm; packing, non-porous stainless steel micro-balls) in the firstdimension and a GPC column set (3×PLgel 10 μm Mixed B column fromPolymer Labs, UK) in the second dimension. Downstream from the GPCcolumn was an infrared detector (IR4 from Polymer Char) capable ofgenerating an absorbance signal that is proportional to theconcentration of polymer in solution.

The sample to be analyzed was dissolved in ortho-dichlorobenzene, at aconcentration of about 5 mg/ml, by stirring at 150° C. for 75 min. Thena 0.5-ml volume of the solution containing 2.5 mg of polymer was loadedin the center of the TREF column and the column temperature was reducedand stabilized at ≈2120° C. for 30 min. The column was then cooledslowly (0.2° C./min) to 30° C. (for ambient runs) or −15° C. (forcryogenic runs) to crystallize the polymer on the inert support. The lowtemperature was held for 10 min before injecting the soluble fractioninto the GPC column. All GPC analyses were done using solventortho-dichlorobenzene at 1 ml/min, a column temperature of 140° C., andin the “Overlap GPC Injections” mode. Then the subsequenthigher-temperature fractions were analyzed by increasing the TREF columntemperature to the fraction set-points in a stepwise manner, letting thepolymer dissolve for 16 min (“Analysis Time”), and injecting thedissolved polymer into the GPC column for 3 min (“Elution Time”).

The universal calibration method was used for determining the molecularmass of eluting polymers. Thirteen narrow molecular-weight distributionpolystyrene standards (obtained from Polymer Labs, UK) within the rangeof 1.5-8200 Kg/mol were used to generate a universal calibration curve.Mark-Houwink parameters were obtained from Appendix I of “Size ExclusionChromatography” by S. Mori and H. G. Barth (Springer). For polystyreneK=1.38×10⁻⁴ dl/g and α=0.7; and for polyethylene K=5.05×10−4 dl/g andα=0.693 were used. Fractions having a weight % recovery (as reported bythe instrument software) of less than 0.5% were not processed forcalculations of molecular-weight averages (Mn, Mw, etc.) of theindividual fractions or of aggregates of fractions.

TABLE 1 Reactor settings and test results from pilot plant run REACTORC6/C2 AI MFR BED TEM RATIO Activity LAB EXT I21/I2 LAB EXT Cat Part BTODEG ° C./C. mol ratio H2 PPM XRF MI(I2) Extruded DENS EXCEED 1018 5.2885.0 0.02160 140.5 0.903 16.385 0.9172 EXCEED 1018 6.31 85.0 0.02106144.6 7834 0.954 16.160 0.9178 EXCEED 1018 7.33 85.0 0.02100 146.8 0.95116.212 0.9180 EXCEED 1018 8.36 85.0 0.02101 146.7 5353 0.945 15.6700.9178 catalyst A 5.02 79.0 0.01439 368.0 6856 1.064 22.502 0.9162catalyst A 5.94 79.0 0.01429 361.3 1.060 22.188 0.9166 catalyst A 7.0279.0 0.01408 355.2 5735 1.045 21.606 0.9168 catalyst A 7.94 79.0 0.01394349.2 1.070 22.111 0.9169 catalyst A 8.87 79.0 0.01362 337.1 5568 1.08021.751 0.9184 catalyst A 9.93 79.0 0.01360 337.0 1.138 21.984 0.9183catalyst A 10.85 79.0 0.01358 337.3 6973 1.148 22.030 0.9187 catalyst A11.84 79.0 0.01359 318.8 1.037 21.943 0.9189 catalyst B 18.64 79.00.01808 262.7 3569 0.970 17.296 0.9185 catalyst B 19.67 79.0 0.01808262.4 1.030 16.889 0.9184 catalyst B 20.63 79.0 0.01806 261.8 3651 1.12017.439 0.9184 catalyst B 21.61 79.0 0.01807 262.4 1.131 17.274 0.9183catalyst B 22.57 79.0 0.01806 262.1 3576 1.122 16.758 0.9186 catalyst B18.64 79.0 0.01808 262.7 0.970 17.296 0.9185

TABLE 2 Settings for Blown Film (1 mil, 25.4 μm) Resin Exceed 1018Catalyst A Catalyst B Film Line 2.5″ GEC 2.5″ GEC 2.5″ GEC Nominal Gauge(mil) 1.0 1.0 1.0 Die Gap (mil) 60 60 60 BUR 2.5 2.5 2.5 Melt (° F.) 403399 400 FLH (in) 18 18 17 Rate lb/hr 189 189 189 lb/in die 10.05 10.0110.02 Head Pressure (psi) 3950 3450 3570 % motor load 69.1 62.9 65.7Energy Specific Output 8.56 9.51 9.15 (lb/HP/hr)

TABLE 3 1 mil film property data Sample Identification Enable ResinExceed 1018 Catalyst A Catalyst B 2010CB Film Line 2.5″ GEC 2.5″ GEC2.5″ GEC 2.5″ GEC MI (g/10 min) 0.94 1.10 1.10 0.96 HLMI 14.6 23.1 19.532.7 (g/10 min) MFR 15.6 21.1 17.8 34.1 Density (g/cc) 0.9185 0.91800.9191 0.921 Gauge (mils) Average 1.00 1.010 1.010 0.99 Low 0.89 0.9100.900 0.87 High 1.09 1.090 1.090 1.10 1% Secant (psi) MD 25,074 26,08930,598 29,602 TD 25,772 32,445 36,612 34,867 Tensile Yield Strength(psi) MD 1,363 1,344 1,615 1,428 TD 1,332 1,391 1,630 1430 Elongation @Yield (%) MD 7.0 6.0 7.7 6.3 TD 5.5 5.4 9.0 4.6 Tensile Strength (psi)MD 10,457 10,129 8,375 8808 TD 8,644 8203 7,642 7393 Elongation @ Break(%) MD 512 456 472 501 TD 658 688 694 724 Elmendorf Tear MD (gms/mil)247.7 216.4 102.4 99.4 TD (gms/mil) 408.1 461.2 560 627.5 Dart Drop,Method A Phenolic (gms/mil) 699.5 618.3 273.8 172 Puncture Method PeakForce 12.82 11.05 13.51 10.84 (lb/mil) Break Energy 42.52 33.53 41.4428.52 (in-lb/mil) Haze (%) 11.2 9.0 3.7 8.9 Gloss 45° MD 44.4 60.1 80.857.8 TD 48.2 65.1 81.6 63.0 Average 46.3 62.6 81.2 60.4

TABLE 4 Differential data for 1 mil films using Exceed 1018 as controlExceed Sample description control Catalyst A Catalyst B Enable 2010 MeltTemp. (F.) 403 399 400 399 Head Prss (psi) 3950 3450 3570 3450 % motorload (%) 69.1 62.9 65.7 62.9 Spec. Output (lb/h/rpm) 3.13 3.16 3.17 3.16E. Spec. Output (lb/hph) 8.56 9.51 9.15 9.51 MD Modulus (psi) 25,07426,089 30,598 29,602 TD Modulus (psi) 25,772 32,445 36,612 34,867 MDYield (psi) 1,363 1,344 1,615 1,428 TD Yield (psi) 1,332 1,391 1,6301,430 MD Tensile (psi) 10,457 10,129 8,375 8,808 TD Tensile (psi) 8,6448,203 7,642 7,393 Puncture PF (lb/mil) 12.82 11.05 13.51 10.84 PunctureBE (in * lb/mil) 42.52 33.53 41.44 28.52 MD Tear (g/mil) 248 216 102 99TD Tear (g/mil) 408 461 560 628 Dart Impact (g/mil) 700 618 274 172Gloss 46 63 81 60 Haze (%) 11.2 9.0 3.7 8.9 (−delta F.) Melt Temp. 0.04.0 3.0 (−delta F.) (−% diff) Head Prss 0.0 12.7 9.6 (−% diff) (−% diff)Motor Load 0.0 9.0 4.9 (−% diff) (−% diff) Specific Output 0.0 1.0 −1.3(% diff) (% diff) E. Spec. Output 0.0 11.1 6.9 (% diff) (% diff) MDModulus 0.0 4.0 22.0 18.1 (% diff) (% diff) TD Modulus 0.0 25.9 42.135.3 (% diff) (% diff) MD Yield 0.0 −1.4 18.5 4.8 (% diff) (% diff) TDYield 0.0 4.4 22.4 7.4 (% diff) (% diff) MD Tensile 0.0 −3.1 −19.9 −15.8(% diff) (% diff) TD Tensile 0.0 −5.1 −11.6 −14.5 (% diff) (% diff)Puncture PF (% 0.0 −13.8 5.4 −15.4 diff) (% diff) Puncture BE (% 0.0−21.1 −2.5 −32.9 diff) (% diff) MD Tear 0.0 −12.6 −58.7 −59.9 (% diff)(% diff) TD Tear 0.0 13.0 37.2 53.8 (% diff) (% diff) Dart Impact 0.0−11.6 −60.9 −75.4 (% diff) (% diff) Gloss (% diff) 0.0 35.2 75.4 30.5(−5X delta) Haze 0.0 11.3 37.6 11.5 (−5X delta)

TABLE 5 Property data for 2-mil films Sample Exceed EnableIdentification 1018 Catalyst A Catalyst B 2010CB Film Line 2.5″ GEC 2.5″GEC 2.5″ GEC 2.5″ GEC Gauge (mils) Average 2.04 2.03 2.07 1.99 Low 1.811.88 2.02 1.83 High 2.21 2.14 2.13 2.11 1% Secant (psi) MD 26,166 26,73828,423 29,425 TD 29,214 32,529 32,285 33,677 Tensile Yield Strength(psi) MD 1,340 1,382 1,435 1,383 TD 1,432 1,475 1,479 1,501 Elongation @Yield (%) MD 6.3 7.9 6.8 6.0 TD 7.5 6.9 5.8 5.9 Tensile Strength (psi)MD 8,431 7,968 7,501 7,943 TD 7,467 7977 8,194 7,090 Elongation @ Break(%) MD 603 584 591 643 TD 661 701 732 743 Elmendorf Tear MD (gms/mil)264.5 232.1 165 173.3 TD (gms/mil) 358.9 400.4 509.4 642.2 Dart Drop,Method A Phenolic (gms) (gms/mil) 628.9 635.0 363.3 214 Puncture MethodB Peak Force 11.54 10.78 11.04 10.67 (lb/mil) Break Energy 40.72 36.2037.34 32.0 (in-lb/mil) Haze (%) 15.5 14.2 9.0 9.0 Gloss 45° MD 45.0 53.666.4 63.1 TD 48.5 53.2 68.5 65.4 Average 46.8 53.4 67.5 64.3 Dart Dartmaxed out maxed out

TABLE 6 Differential data for 2-mil films using Exceed 1018 as controlSample description Exceed 1018 Catalyst A Catalyst B Enable 2010 MDModulus (psi) 26,166 26,738 28,423 29,425 TD Modulus (psi) 29,214 32,52932,285 33,677 MD Yield (psi) 1,340 1,382 1,435 1,383 TD Yield (psi)1,432 1,475 1,479 1,501 MD Tensile (psi) 8,431 7,968 7,501 7,943 TDTensile (psi) 7,467 7,977 8,194 7,090 Puncture PF (lb/mil) 11.54 10.7811.04 10.67 Puncture BE (in * lb/mil) 40.72 36.20 37.34 32.04 MD Tear(g/mil) 265 232 165 173 TD Tear (g/mil) 359 400 509 642 Dart Impact(g/mil) 629 635 363 214 Gloss 47 53 67 63 Haze (%) 15.5 14.2 9.0 9.0Comparative Data Exceed Product Code control Catalyst A Catalyst BEnable 2010 (% diff) MD Modulus 0.0 2.2 8.6 12.5 (% diff) (% diff) TDModulus 0.0 11.3 10.5 15.3 (% diff) (% diff) MD Yield 0.0 3.1 7.1 3.2 (%diff) (% diff) TD Yield 0.0 3.0 3.3 4.8 (% diff) (% diff) MD Tensile 0.0−5.5 −11.0 −5.8 (% diff) (% diff) TD Tensile 0.0 6.8 9.7 −5.0 (% diff)(% diff) Puncture PF 0.0 −6.6 −4.3 −7.5 (% diff) (% diff) Puncture BE0.0 −11.1 −8.3 −21.3 (% diff) (% diff) MD Tear 0.0 −12.2 −37.6 −34.5 (%diff) (% diff) TD Tear 0.0 11.6 41.9 78.9 (% diff) (% diff) Dart Impact0.0 1.0 −42.2 −66.0 (% diff) (% diff) Gloss (% diff) 0.0 11.6 41.9 78.9(−5X delta) Haze 0.0 6.5 32.6 32.3 (−5X delta)

All numerical values are “about” or “approximately” the indicated value,and take into account experimental error and variations that would beexpected by a person having ordinary skill in the art. Further, variousterms have been defined above. To the extent a term used in a claim isnot defined above, it should be given the broadest definition persons inthe pertinent art have given that term as reflected in at least oneprinted publication or issued patent. All patents, test procedures, andother documents cited in this application are fully incorporated byreference to the extent such disclosure is not inconsistent with thisapplication and for all jurisdictions in which such incorporation ispermitted.

While the foregoing is directed to embodiments of the present invention,other and further embodiments of the invention can be devised withoutdeparting from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

What is claimed is:
 1. A catalyst composition comprising a catalystcompound supported to form a supported catalyst system, wherein thecatalyst compound comprises:

wherein Each X is independently a leaving group selected from a halogen,a labile hydrocarbyl, a substituted hydrocarbyl, or a heteroatom group.2. The catalyst composition of claim 1, comprising an activatorcomprising an acid derived from a weakly coordinating anion.
 3. Thecatalyst composition of claim 2, wherein the activator comprises analuminoxane compound, an organoboron, an organoaluminum compound orcombinations thereof.
 4. The catalyst composition of claim 2, whereinthe activator comprises methyl aluminoxane or modified methylauminoxane.5. The catalyst composition of claim 1, comprising a support comprisinga mineral, a clay, a metal oxide, a metalloid oxide, a mixed metaloxide, a mixed metalloid oxide, a mixed metal-metalloid oxide, apolymer, or any combinations thereof.
 6. The catalyst composition ofclaim 5, wherein the support is a polyolefin or a polyolefin derivative.7. The catalyst composition of claim 5, wherein the support has beenthermally treated and/or chemically treated with an acid, anorganoaluminum, or a fluoriding agent, or any combinations thereof. 8.The catalyst composition of claim 5, wherein the support has beenthermally treated.
 9. The catalyst composition of claim 5, wherein thesupport comprises silica, alumina, aluminosilicate, titanated silica, ortitanated alumina, or any combinations thereof.
 10. The catalystcomposition of claim 1, comprising a silica support and a methylaluminoxane activator.